On random occasions the preform being fed by the loading means of U.S. Pat. No. 3,958,685 FIGS. 6 and 7 jams in a position between the track and the coupling. Some of the reasons for jamming are warped preforms and assumption of a cocked position in the coupling. Whatever the reason, jamming at this location has led to damage of the machine and the preform and a consequent loss of production.
Simply stated, the present invention provides a spring mounted end for the loading chute track. This permits the loading means to resiliently give in response to a jammed or misaligned preform being pulled forcefully out of the track end for the coupling which has engaged it during loading. The prior structure (e.g. the cited U.S. Patent) was sufficiently rigid and not able to "give" or move out of the way that damage to the machine and/or preform often resulted.
More broadly, the present invention provides a resiliently supported stop member at the end of the feed chute track in the aforesaid loading means.
Thus, the present invention provides a machine for use in feeding a series of workpieces along a path to a predetermined location, each workpiece being elongated and having an enlarged head at one end and a body of smaller dimension than said head, said machine having a pair of upper tracks with upwardly facing support surfaces for engaging the underside of each said head and being spaced apart laterally sufficiently to receive said workpiece body therebetween and to support same by its head on said surfaces, at one end of at least one of which tracks is a stop shoulder extending laterally at least enough to engage said head and to prevent its passage, the improvement comprising a resilient mounting of the stop shoulder adjacent said end with a structure that includes said stop shoulder being structurally separate from said track and extending approximately laterally as aforesaid, and resilient means for supporting said stop shoulder to allow approximate lateral motion of said stop shoulder responsive to a workpiece being moved past said stop shoulder in a direction at least partly along said track.